Our Story

The roots of K.Jons Diamonds & Gems stretch back more than 50 years. The business literally started from the ground up. Kay and John, Stan’s parents and the namesakes of K.Jons, were avid rockhounds and gem and mineral enthusiasts. Stan grew up learning to appreciate nature’s wonders on family camping trips looking for geodes, agate, fire agate, and petrified wood, as well as other stones. He learned to cut and polish stones and opals before he was ten. Precious opals continue to be one of his favorite gemstones.


Stan met Mary while both attending Cal Poly in San Luis Obispo, and they were soon married. Together, they continued to pursue their interest in gems and started traveling the western states as gem dealers. This led to the opening of K.Jons Diamonds & Gems in May of 1980, as they desired a more stable lifestyle for their growing family. Outgrowing their original store in Atascadero, they were excited to move into their new showroom at the same location in 2004. Stan and Mary Sherwin are proud that K.Jons Diamonds & Gems is recognized as the prominent jewelry store on the Central Coast. They and their crew are passionate about quality gemstone and diamond jewelry and providing excellent service for their customers.

In keeping with our strong beliefs in ethics, value, and continuing education, K.Jons Diamonds & Gems is honored to be a member of the American Gem Society (AGS). AGS has strict ethical and professional requirements and less than 5% of jewelers nationwide are able to qualify for membership. We are proud of the honor and responsibility that AGS membership brings with it.